Biomolecular condensates at the nuclear pore basket maintain global chromatin organization
Nuclear pore complexes are the only gateway between the nucleus and cytoplasm in eukaryotic cells during interphase. Specificity of transport is ensured by a size-dependent permeability barrier, which has so far been attributed to intrinsically disordered phenylalanine-glycine (FG) repeat- containing nucleoporins located in the central channel of the nuclear pores. We show that the coiled-coil domain of the main component of the nuclear pore basket, the non-FG protein TPR, encompasses intrinsically disordered regions. This "disordered coiled-coil domain" allows it to form biomolecular condensates in vivo, drives mechanical exclusion of heterochromatin, and defines a new permeability barrier at the nuclear basket. This work therefore highlights unconventional properties of coiled-coil domains at the nuclear pore basket and bridges the biophysics of such domains with nuclear architecture, chromatin spatial organization and nucleocytoplasmic transport.